A group of scientists in collaboration with the UN Food and Agricultural Organization (FAO) conducted two new studies that have shown the emergence of two new groups of rust across various regions of the world in 2016. These are named yellow rust and stem rust.
The FAO-supported reports have been highlighted in the journal Nature following their publication by Aarhus University and the International Maize and Wheat Improvement Center (CIMMYT).
Key highlights of the studies
• The studies show that wheat in Africa, Asia and Europe is increasingly threatened by fresh groups of wheat rust.
• The most recently identified race of stem rust pathogen, called TTTTF, hit the Italian island of Sicily in 2016, causing the largest stem rust outbreak in Europe in decades.
• Farmers in the mainland Italy, Morocco and some Scandinavian countries are battling a yet-to-be-named race of yellow rust.
• On the other hand, Ethiopia and Uzbekistan are fighting outbreaks of yellow rust AF2012.
What is wheat rust?
• Wheat rust belongs to a family of fungal diseases that can cause crop losses of up to 100 percent in untreated susceptible wheats.
• Infections can lead up to 20 per cent yield loss exacerbated by dying leaves, which fertilize the fungus.
• Wheat rusts spread rapidly over long distances by wind. They, if not detected and treated on time, can turn a healthy crop into a tangle of yellow leaves, black stems and parched grains.
• The disease spreads via airborne spores. Five types of spores are formed in the life cycle. Uredospores, teleutospores, and basidiospores develop on wheat plants and pycnidiospores and aeciospores develop on the alternate hosts.